|Fig. 1032.12 Convex and Concave Sphere Packing Voids:
- In a tetrahedron composed of four spheres, the central
void is an octahedron with four concave
spherical triangular faces and four planar triangular
faces with concave sides. This can be described
as a "concave octahedron."
- In an octahedron composed of six close-packed spheres,
the central void is a vector equilibrium with
six concave spherical square faces and eight triangular
faces with concave sides: a "concave vector
- The vector equilibrium with edges arced to form a
sphere: a convex vector equilibrium.
- The vector equilibrium with arcs on the triangular
faces defined by spheres tangent at vertexes: a
concave vector equilibrium.
Copyright © 1997 Estate of R. Buckminster Fuller